42. We may infer from the passage that the imprints of the smith’s thumbs or lips are impressed upon the blade because _______. (A) some decorative materials such as ivory and gold are much more valuable than wood (B) the imprints help shield the owner of the kris from evil spirits (C) it is a symbol of the royalty heirloom (D) forging the blade can be painstaking and dangerous for the smith